Abstract:Blanket fertilizer recommendations, especially for nitrogen can lead to the overuse of fertilizers and wasteful use of nutrients. Thisgenerated a necessity to discovertactics to increase crop production while reducing cultivation costs and improving the monetary efficiency of crops.Field investigationswere led during 2015and 2016 at Anand, India to find critical threshold values of leaf greenness as measured by LCC and CCM for framingapproaches for fertilizerNmanagementin maize.Across the years,nitrogenapplication based on LCC threshold value 5, CCM threshold value 40 and blanket recommendation (100% RDF)significantly (P<0.05) increased the crop growth in terms of plant height, number of leaves plant-1, dry matter production (g) plant-1 and leaf area index of maize compared to other treatments.Almost similar trends were observed with respect to yield attributes viz., the number of cobs plant-1, cob length (cm), the average weight of cob (g), number of grains cob-1 and weight of 100 grains (g).
The absolute growth rate at 60-90 DAS (g day-1) and crop growth rate (g m-2 day-1) recorded at different intervals found superior under N application based on LCC critical value 5 and CCM critical value 30 and did not differ significantly with other treatments except CCM 30 and LCC 3 throughout the years. Assessment of the thresholdleaf greenness revealed that fertilizer N management using LCC 5 and CCM 40 resulted in increased grain and straw yields in maize. The increment in grain yield of maize over blanketrecommendation was to the tune of 12.30 and 12.25 percent in LCC 5during 2015 and 2016, respectively.Net profit from the maize under LCC 5 was up to 16.
37 percenthigher compared to blanket (100% RDF).The study revealed that in maize, fertilizer N can be more effectively managed by applying fertilizer N dose based on leaf color as measured by LCC than blanket recommendation.Keywords:Blanket Recommendation, CCM, Fertilizer, LCC, Maize, Nitrogen and Yield Abbreviations: LCC- Leaf Color Chart, CCM- Chlorophyll Content Meter, RDF- Recommended Dose of Fertilizers, DAS- Days After Sowing Introduction:In food production, Fertilizer nitrogen (N) has turn into the key contribution.The nitrogen has a significant importance in the construction of amino acids, chlorophyll other organic complexes which add to the building units of proteins in the plant system.
Photosynthetic activity of the plants and their ability to make use of existing soil nutrients is increases with application of nitrogen. Nitrogen enhances the growth, dry matter accumulation and yield of crops even under dry land situations. Cereals including rice, wheat, and maize represents for a greater portion (more than 50%) of the total Nfertilizer utilization in the globe. According to estimations, 50-70% additional cereal grains will be required by 2050 to nourish over 9 billion world population (Varinderpal-Singh etal. (2011). This will promoteaugmented demand for fertilizer N at largerextent unless therecovery efficiency of fertilizer N in cereals is upgraded. It is merely 30-50% by the first crop and not greater than 7% by the six successive crops (Ladhaetal., 2005).
N losses from the soil plant system are large if the N application is non-synchronized with crop demand. The normal practice of unnecessary fertilizer N applications to avoid the risk of N deficiency further diminishes this efficiency. Excess of N application results in nutrient imbalances and produces plants that are disease and pest vulnerable.
Low recovery of N is not solitaryaccountable for higher cost of crop production, but also for environmental pollution (Fageria and Baligar, 2005). Fixed-time application of fertilizer N doses at specified growth stages (Blanket recommendations) do not reflect the active soil N supply and crop N demands and lead to unfortunate and untimely application of fertilizer N. Hence, demand driven need based and real time fertilizer N management in crops can help inincrease N recovery efficiency and to shrink N losses.
Conventional tissue testing procedures are the common methods to accessin-season, N requirement of crop plants. Observingseasonal N availability and N status of a crop tissue has benefits that plant integrates N supply over a period of time and hence can reveal N supply as influenced by soil processing, weather and fertilization. Conversely, for receiving a fertilizer recommendation plant tissue analysis takes 10-14 days from tissue sampling and does not seem to be anappliedproposal.